<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin:0;
            padding:0;
        }
        div{
            height:10px;
            width:200px;
            background-color: aqua;
            margin: 50px auto;
            /* display: block; */
            opacity: 1;
            /* 过渡(display不起作用)
            过渡的属性 过渡的时间(秒) 过渡的动画 延迟时间

            all 多属性过渡
             */

            transition:all 5s ease-out 1s;

            /* transition-property: height;
            transition-duration: 5s;
            transition-timing-function: ease-out;
            transition-delay: 1s; */
        }
        div:hover{
            /* display: none; */
            opacity: 0;
            height:100px;
            background-color: aquamarine;
        }
    </style>
</head>
<body>
    <div></div>
</body>
</html>